Fuel vaporizer system with fuel injection

ABSTRACT

A fuel vaporizer including fuel injectors is described herein. The vaporizer includes a housing having a plurality of baffles defining a plurality of chambers, with each of the plurality of baffles defining an aperture between adjacent chamber, and the apertures define a flow path from the air inlet, through the plurality of chambers, and to the vapor outlet. A conduit extends through the baffles and chambers, and the conduit is adapted to accept a flow exhaust gas and transfer thermal energy from the exhaust gas to an airflow along the flow path A fuel injector is positioned in the housing to inject fuel into the flow path in the first chamber, the thermal energy from the conduit vaporizing the fuel injected into the airflow and producing the flow of vaporized fuel. The fuel vaporizer may include a heat exchanger pre-heating the airflow and electric heating elements supplementing the conduit heating.

FIELD

The present invention relates to fuel conditioning systems and moreparticularly to conditioning systems that vaporize the fuel to achieveenhanced energy recovery.

BACKGROUND

Consumers have long demanded higher fuel efficiency. One line oftechnological development to meet this demand has involved changing thestructure of the vehicle. Size, shape and offered features impact themiles per gallon. Perhaps the most efficient of vehicles using this lineof technology is the motorcycle, which most commonly get about fiftymiles to the gallon.

Another line of technology focuses on the fuel itself. People have knownthat liquid fuel does not burn. Vapors around the liquid will burn. Infact, chemists will state that if one could put a lit match into liquidfuel in the absence of vapors, the match will extinguish. In typicalvehicles, some believe that only about 18% of the fuel is in vapor formprior to and during ignition in the internal combustion engines. Thebalance of the fuel is sent out of the vehicle through the exhaustsystem. The catalytic converter conditions the unconsumed fuel prior torelease into the atmosphere. Technology, focusing on conditioning of thefuel, vaporizes a greater percentage of the fuel, thereby gaining animprove energy recovery.

Generally, the vaporizing devices use excess energy from the engine.Heat energy can be drawn off the exhaust or cooling system. Some use theexcess electrical energy as an energy supply. This energy is transmittedto the fuel usually in one of a few manners. The most popular appear tobe mist vaporizers and boilers.

Mist vaporizing systems in general terms atomize the fuel into a mistform and apply heat to convert the mist into a vapor. These systems takeadvantage of the fact that mist, has far greater surface area, making itmore readily converted to vapor, than a pool of fuel. Unfortunatelythese mist vaporizing systems are generally not operational until afterthe vehicle has warmed, since the atomized fuel tends to pool beforeheat is abundant and pooling fouls the system. Wasteful adaptation toaddress the pooling are found in most of these systems.

As an example, Covey Jr. (U.S. Pat. No. 5,291,900) discloses a FuelVaporizing System. The system has an inner and outer housing with atemperature probe therebetween. Exhaust passes between the inner andouter housings. Atomized fuel is injected into the inner housing. Thefuel, mist form, is converted to vapor as it rises through a series ofbaffles. This system, by its own admission, is not operational until theprobe detects a temperature of at least 550 degree F. The waste here isin not being able to use the system until the vehicle has warmed welland the waste is experienced in cold climates and on short trips.

Covey Jr. (U.S. Pat. No. 4,368,163) discloses an Apparatus forVaporizing Fuel for Engine in Conjunction with Carburetor. Atomized fuelis sprayed at a conduit containing exhaust. The conduit, a heatexchanger, causes the mist to vaporize. Any mist that fails to vaporizepools in a well and is drained back into the fuel line. This inventionis wasteful in requiring additional apparatus to merge two streams offuel and having lower vapor production in cold climates and on shorttrips.

A boiler system may be used to evaporate fuel from a pool of liquidfuel. This has the advantage of being useable before the exhaust orcooling systems are fully heated. However, boilers are inefficient andhave lower vapor production in that they do not take advantage of thewell accepted atomizer technology, which greatly increases the surfacearea of the fuel and eases the conversion liquid fuel to vapor.

For example, Lahti et al. (U.S. Pat. No. 6,415,775) discloses a PreheatFuel Delivery System. This system directs air through a bubbler tank.Vapors are collected above the pool of fuel. Advantageously, this systemwill work when fuel pools. Unfortunately, the surface area from whichthe fuel may vaporize is greatly reduced from the surface area thatwould be present should the fuel be heated from a mist form. This systemcompensates for low vapor production, routing exhaust into the bubbler,which unfortunately mixes carbon dioxide (not oxygen) with the vaporizedfuel.

Cook (U.S. Pat. No. 5,746,188) discloses another example of a boilersystem entitled Apparatus for Supplying Fuel to an Internal CombustionEngine. Liquid fuel is injected into the interior of the housing. Theliquid fuel passes through openings in the baffles gathering heat andeventually vaporizing prior to exiting the housing. Advantageously, thissystem will work when fuel pools. Unfortunately, the surface area fromwhich the fuel may vaporize is greatly reduced from the surface areathat would be present should the fuel be heated from a mist form,yielding lower vapor production.

What is needed is a fuel vaporization system that vaporizes fuel whilein a mist form and yet will also vaporize, e.g., boil, fuel while in apooled form. The system should avoid the waste attendant with evacuatingor avoiding pooled fuel and likewise should capture the higher vaporproduction attainable when vaporizing fuel in a mist form. Desirably,the components are minimal and are used both for vaporizing the mist andboiling the fuel pools.

SUMMARY OF THE INVENTION

Certain aspects of the present disclosure relate to a fuel vaporizationsystem that vaporizes fuel while in a mist form and simultaneouslyvaporizes, e.g., boils, fuel while in a pooled form. Certain aspectsavoid the waste attendant with evacuating or avoiding pooled fuel andlikewise has the higher vapor production attainable the vaporizing fuelin a mist form. The components are minimal and are used both forvaporizing the mist and boiling the fuel pools, e.g. the systems areintegrated.

One example is a fuel vaporizer having a fuel injection system. The fuelvaporizer includes a housing having a plurality of baffles joined to thehousing, the housing and baffles defining a plurality of chambers, eachof the plurality of baffles defining an aperture between adjacentchamber, an air inlet in a first chamber of the plurality of chambers,an vapor outlet in a last chamber of the plurality of chambers, theapertures defining a flow path from the air inlet, through the pluralityof chambers, and to the vapor outlet, and a conduit extending throughthe baffles and chambers, the conduit adapted to accept a flow ofexhaust gas therethrough, the conduit positioned in the flow path, andthe conduit adapted to transfer thermal energy from the exhaust gas toan airflow along the flow path. The fuel vaporizer also includes a fuelinjector positioned in an opening in the housing, with the fuel injectoradapted to inject fuel into the flow path in the first chamber. Thehousing is adapted to accept the airflow at the air inlet and produce aflow of vaporized fuel to the vapor outlet. In operation, the thermalenergy from the conduit vaporizes the fuel injected into the airflow andproduces the flow of vaporized fuel.

In one example, the fuel vaporizer may include a housing joined tobaffles. Conduit is in thermal communication with exhaust and is inthermal communication with fuel in a mist form. The conduit may also bein thermal communication with the baffles. The baffles are in thermalcommunication with the housing. The baffles and housing contain and are,at least optionally, in thermal communication with a pool of fuel.

In another example, the fuel vaporizer may include a housing. Conduitextends through the housing. At least one turbulator may be joined tothe conduit.

Advantageously, the present invention combines the technologies of mistvaporizers and boilers in a single simplified unit.

As yet another advantage, the present invention simultaneously vaporizesfuel in a mist form and in a pooled liquid form.

As still yet another advantage, the present invention includes aturbulator to cause turbulence in the exhaust passing through theconduit, increasing thermal transfer from the exhaust to the conduit.

Further, the present invention uses the same conduit to transfer heatenergy to a boiler and to fuel in a mist form.

Also as an advantage, the present invention utilizes a housing andbaffles to define a fuel passageway and to define a boiler to containfuel and vaporize fuel in a liquid form.

In some examples, the fuel vaporizer defines an exhaust inlet chamberand an exhaust outlet chamber in flowable fluid communication throughthe conduit. In some examples, conduit is a matrix of a pluralityconduits. In some examples, the conduit includes a turbulator joinedinside the conduit.

In some examples, the fuel vaporizer includes an electric heatingelement adapted to heat the conduit, the heating element enablingelectric heating of the airflow through the flow path. The heatingelement may be integrated with the plurality of baffles. The heatingelement may be integrated with the conduit.

In some examples, the fuel vaporizer includes a heat exchanger inthermal connection with the outer surface of the housing. The heatexchanger defines an internal flow path in flowable fluid communicationwith the air inlet of the housing, and the heat exchanger is adapted toheat the airflow along the internal flow path with thermal energy fromthe housing prior to the airflow entering the air let of the housing.

In some examples, the fuel injector is a first fuel injector in a firstopening in the housing, and the fuel vaporizer further includes a secondfuel injector positioned in a second opening in the housing, with thesecond fuel injector adapted to inject fuel into the flow path in thefirst chamber.

In some examples, a second fuel injector is positioned in a secondopening in the housing, with the second fuel injector adapted to injectfuel into the flow path in a second chamber, the second chamber beingadjacent to the first chamber. In some examples a third fuel injectorpositioned in a third opening in the housing, with the third fuelinjector adapted to inject fuel into the flow path in a third chamber,the third chamber being adjacent to the second chamber.

Another example is a method of operating an internal combustion engine,given a fuel, an airflow, and exhaust gas from the internal combustionengine. The method includes flowing the exhaust gas through a conduit,the conduit passing through a plurality of chambers formed by aplurality of baffles, the exhaust gas transferring thermal energy to theconduit, flowing the airflow through the plurality of chambers, theairflow flowing around the conduit, injecting the fuel in the airflow ofa first chamber of the plurality of chambers, the injecting atomizingthe fuel in the airflow, transferring thermal energy from the conduit tothe airflow in the plurality of chambers, the thermal energy vaporizingat least a portion of the fuel in the airflow and generating a flow ofvaporized fuel, and providing the flow of vaporized fuel to an intake ofthe internal combustion engine.

In some examples, flowing the exhaust gas through a conduit includesflowing the exhaust gas through a matrix of a plurality of conduits.

In some examples, flowing the airflow through the plurality of chambersincluding the airflow flowing through the matrix of the plurality ofconduits in each of the plurality of chambers.

In some examples, flowing the exhaust gas through a conduit furtherincludes adding turbulence to the flow of exhaust gas inside theconduit.

In some examples, the method includes injecting the fuel in the airflowin a second chamber of the plurality of chambers.

In some examples, transferring thermal energy from the conduit to theairflow in the plurality of chambers includes heating the airflow in thefirst chamber to at least 725 degrees Fahrenheit. In some examples,transferring thermal energy from the conduit to the airflow in theplurality of chambers includes heating the airflow in a last chamber toat least 450 degrees Fahrenheit.

In some examples, the thermal energy vaporizes at least 50% of the fuel.In some examples, the thermal energy vaporizes at least 80% of the fuel.

In some examples, the method further includes transferring thermalenergy to the conduit with an electric heating element. In someexamples, transferring thermal energy to the conduit with an electricheating element includes regulating a temperature of the airflow usingthe transferring of thermal energy to the conduit from the electricheating element. The regulating may be based on a temperature of one ormore of the following: the exhaust gas, the conduit, and the airflow.

In some examples, flowing the exhaust gas through a conduit includesregulating the flow of exhaust gas through the conduit to maintain atemperature of the airflow in at least one of the first chamber and theintake.

In some examples, the method further includes, prior to the injectingthe fuel in the airflow of a first chamber, starting the internalcombustion engine using a fuel injection system of the internalcombustion engine, and transitioning from the fuel injection system ofthe internal combustion engine to injecting the fuel in the airflow of afirst chamber, the transitioning being based on a temperature of theairflow or a temperature of the conduit.

Yet another example is a method of operating an internal combustionengine, given a fuel, an airflow, and exhaust gas from the internalcombustion engine. The method includes flowing the exhaust gas through aconduit, the conduit passing through a plurality of chambers formed by aplurality of baffles, flowing the airflow through the plurality ofchambers, the airflow flowing around the conduit, injecting the fuel inthe airflow of a first chamber of the plurality of chambers, theinjecting atomizing the fuel in the airflow, transferring thermal energyfrom an electric heating element to the airflow in the plurality ofchambers, the thermal energy vaporizing at least a portion of the fuelin the airflow and generating a flow of vaporized fuel, and providingthe flow of vaporized fuel to an intake of the internal combustionengine.

These and other advantages will become apparent from reading the belowdescription of the preferred embodiment with reference to the appendeddrawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic drawing of the exhaust system.

FIG. 2 is a schematic drawing of the fuel system.

FIG. 3 is a top view of the throttle.

FIG. 4 is a side view of the throttle.

FIG. 5 is a side view of the vaporizer.

FIG. 6 is a sectional view taken along the lines 6-6 of FIG. 5.

FIG. 7 is an end view of the central portion of the vaporizer takenalong the lines 7-7 of FIG. 5, showing the conduit and turbulators.

FIG. 8 is a side view of a turbulator.

FIG. 9 is a perspective view of adjacent baffles with the conduitremoved.

FIG. 10 is a perspective view of adjacent baffles with the conduit shownin partial phantom.

FIG. 11 is a schematic of a fuel vaporizer with fuel injectors.

FIGS. 12A and 12B are schematics of a fuel vaporizer with fuel injectorsand a heat exchanger.

The Figures are selected to fully and completely demonstrate thepreferred embodiment of the present invention and are not selected toshow all conceivable modifications that would fall within the scope ofthe claim.

DETAILED DESCRIPTION

The present invention 10 thermally joins an exhaust system 12 and fuelsystem 14 in a vaporizer 16, forming a mist evaporator 18 and a boiler20, the boiler 20 being integrated, e.g., using the same parts, with themist vaporizer 18. The mist evaporator 18 and boiler 20 provide asynergistic effect most efficiently vaporizing fuel 22 to obtain animproved level of vaporization of the fuel 22 prior to entry into aninternal combustion engine 24, hereinafter engine. The exhaust system 12and fuel system 14 will be separately described, culminating in adescription of the mist evaporator 18 and boiler 20.

Exhaust System

FIG. 1 is a schematic drawing of an overview of the exhaust system 12.

The engine 24, which produces exhaust 30, is joined to one or moreexhaust outlets 32, which in turn is/are joined to the exhaust line 34.The exhaust line 34 extends from the engine 24 to the exhaust exit 38.Mid-length, the exhaust line 34 preferably joins to an exhaust valve 36.The exhaust valve 36 directs a portion of the exhaust 30 through aexhaust passageway 40 and directs the balance of the exhaust 30 througha recycling passageway 48, which will be described further below.

The sealed exhaust passageway 40, leading from the engine 24 to theexhaust exit 38 and to the atmosphere, is defined by exhaust outlets 32,exhaust line 34, exhaust valve 36, catalytic converter 42, muffler 44and exit 38. The exhaust outlets 32 of the engine 24 are joined to theexhaust line 34 at an upstream end 46. The exhaust line 34 may be invarious segments and be joined to the exhaust valve 36, catalyticconverter 42, muffler 44 and exit 38. Exhaust 30 from the engine 24 isin flowable communication, through the exhaust passageway 40, with theatmosphere. Preferably, all the exhaust 30 from the engine 24 isultimately in flowable communication, through the exhaust valve 36, witha catalytic converter 42, muffler 44 and the exhaust exit 38, althoughsome exhaust 30 may flow through the exhaust valve 36 and recyclingpassageway 48 prior to the catalytic converter 42, muffler 44 andexhaust exit 38.

The recycling passageway 48 is joined to the exhaust passageway 40 suchthat exhaust 30 in the engine 24 is in flowable communication throughthe conduit 50 prior to the exhaust exit 38. Recycling passageway 48 maybe defined by the exhaust valve 36, first recycling line 52, exhaustinlet 54, exhaust inlet chamber 56, conduit 50, exhaust outlet chamber58, exhaust outlet 60 and second exhaust recycling line 62. Therecycling passageway 48 extends from the exhaust valve 36, through theconduit 50, which may be in the vaporizer 16, and back to the exhaustline 34. Exhaust 30 in the exhaust passageway 40 is, therefore, inflowable communication through the entire recycling passageway 48 andback to the exhaust passageway 40.

The recycling passageway 48 will now be described with specificreference to the components defining the recycling passageway 48. Afirst exhaust recycling line 52 joins to the exhaust valve 36 and to theexhaust inlet 54 of the vaporizer 16, such that exhaust 30 from theengine 24 is in flowable communication with the vaporizer 16. A secondexhaust recycling line 62 may join the exhaust outlet 60 of thevaporizer 16 to the exhaust line 34 either downstream or upstream of theexhaust valve 36, thereby providing a return. The second exhaustrecycling line 62 joins to the exhaust outlet 60 and to the exhaust line34 such that exhaust 30 in the vaporizer 16 (and first exhaust recyclingline 52) is also in flowable communication with the exhaust line 34. Thevaporizer 16, and more particularly the housing 64 and baffles 114define the exhaust inlet chamber 56 and exhaust outlet chamber 58, whichare in flowable communication through the conduit 50. The exhaust 30 inthe vaporizer 16 is desirably not in flowable communication with thefuel 22.

The vaporizer 16, shown in greater specificity in FIGS. 5 and 6, forms aportion of the exhaust recycling passageway 48. FIG. 5 shows the exhaustinlet 54, housing 64 and exhaust outlet 60. The housing 64 may take anyof a variety of shapes sizes and forms. Preferably, the housing 64 isformed of a high thermally conductive material such as copper, aluminumor other material known in the art. The housing 64 may define at least aportion of various chambers 56, 58, 104, 106, 108, 110, and 112,described here and throughout, within the vaporizer 16 (FIG. 6). Theexhaust inlet chamber 54 may be approximately 3″ by 5″ by 5″, theexhaust outlet chamber 58 may be 2″ by 5″ by 5″, while the centralchamber 102 may be 12″ by 5″ by 5″. The exhaust inlet chamber 56 issealably joined to and disposed between the exhaust inlet 54 and conduit50. The exhaust outlet chamber 58 is sealably joined to and disposedbetween the conduit 50 and exhaust outlet 60. The conduit 50 ispreferably formed of a high thermally conductive material such asaluminum, copper or other material known in the art.

The conduit 50 may be joined to a turbulator 66; preferably joinedinside the conduit 50. A turbulator 66 is any mechanism suitable forcausing turbulence in the conduit 50 such that the exhaust 30 thermallymixes within the conduit 50. A suitable turbulator 66 desirably is apiece of flat metal twisted into a spiral, see FIG. 8, having a widthequivalent to an inside diameter of the conduit 50 as shown in FIG. 7.The turbulator 66 may have a length equivalent to the length of theconduit 50 and may be friction fit therein. One skilled in the art cansee that alternative forms of turbulators 64 may be designed. In apreferred embodiment, the turbulator 66 is made from ⅛″ aluminum stock,being ¾″ wide by 12″ long, twisted and put into ¾″ aluminum conduit 50.The turbulators 66 distribute heat and slow down the flow of the exhaust30.

The recycling lines 52, 62 and vaporizer 16 recycle heat energy from theexhaust 30 for use in vaporizing the fuel 22. The conduit 50, whichdefines a portion of the recycling passageway 48 as described above, isin thermal communication with the exhaust 30 and in thermalcommunication with the fuel 22 whether in a mist or liquid form. Theexhaust 30 and fuel 22 are preferably only indirectly in thermalcommunication with each other via the conduit 50. That is, the exhaust30 is contained within the conduit 50, while the fuel 22 is positionedoutside the conduit 50.

In summary, the engine 24 is flowably joined to the exhaust system 12.The exhaust system 12, includes the exhaust passageway 40 that joins tothe recycling passageway 48 at the exhaust valve 36. The exhaust valve36 directs a portion of the exhaust 30 through to continuing portions ofthe exhaust passageway 40 and directs the balance of the exhaust 30through the recycling passageway 48. The recycling passageway 48provides mechanism for recycling heat energy from the exhaust 30 to thefuel 22. Exhaust 30 in the recycling passageway 48 is in flowablecommunication (in and out) with the exhaust passageway 40 and ultimatelyexits to the atmosphere.

Fuel System

The fuel system 10 includes a vaporizer 16 that conditions fuel 22 forcombustion in the engine 24. The fuel system 10 may include a fuel tank70 for fuel storage joined to a fuel line 72. The fuel line 72 may passthrough various components in-line to the internal combustion engine 24.For instance, the fuel line 72 may join to a fuel filter 74, a fuel pump76 and a T-splitter 78.

The T-splitter 78 allows fuel 22 to enter the engine 24, cylindersthereof, in a traditional manner. A fuel transfer tube 80 may join theT-splitter 78 to a throttle 82. The throttle 82 may have an inlet 84joined to a throttle body 88. A choke 86 may be disposed adjacent theinlet 84 the throttle body 88. An air passageway 90, extending from theatmosphere to the throttle body 88, is therefore cooperatively definedby the inlet 84, choke 86, throttle body 88, allowing air to mix withthe fuel 22 in the throttle body 88. Vapor (air) from the atmosphere isin flowable communication with fuel 22 through the air passageway 90. Aswitch disposed inside the passenger area of the vehicle may be used toswitch the flow of fuel 22 at the T-splitter 78 to the throttle body 88or alternatively to the vaporizer 16, depending upon the needs of power.It has been found that the need for increased power, e.g. vehicle isaccelerating or climbing hills, is more efficiently met when the fuel 22flows through the throttle 82 and cruising is more efficient through thevaporizer 16.

The fuel line 72, downstream of the T-splitter 78, may flowably join toa second fuel filter 92, a flow meter 94 and the vaporizer 16. Thevaporizer 16 may be joined to the internal combustion engine 24. Thefuel tank 70, fuel line 72, fuel filter 74, fuel pump 76, T-splitter 78,second fuel filter 88, flow meter 94, vaporizer 16 and engine 24 thusdefine a fuel passageway 96. Fuel 22 from the tank 70 is in flowablecommunication through the fuel passageway 96 with the engine 24. Thefuel 22 is combusted in the engine 24, generating exhaust 30.

The fuel line 72 may be joined to an injector 98 and flowably joined toan atomizer 100, which in turn are joined to the vaporizer 16. Anatomizer 100 is fine mesh screen sized and adapted to split fuel 22 intoa mist when the injector 98 propels fuel 22 against the atomizer 100.Desirably, the injector 98 and atomizer 100 are positioned adjacent afirst chamber 104 of the central portion 102 of the vaporizer 16 suchthat the fuel 22, in mist form, may enter into a first chamber 104 ofthe central portion 102 of the vaporizer 16 above any fuel 22 that maybe pooled therein. Most desirably, the injector 98 and atomizer 100 arejoined to a throttle body 101, similar to that described above andotherwise known in the art. The throttle body 101 may allow butterflyvalves to open upon depression of the gas peddle to allow air to mixwith the misted fuel. The butterfly valves and connection to the gaspeddle is technology known in the art.

The vaporizer 16 desirably includes baffles 114 which join to thehousing 64 to define a plurality of chambers, such as chambers 104, 106,108, 110 and 112, each chamber being sized and adapted to hold a pool offuel 22. The chambers 104, 106, 108, 110 and 112 are intended to bepositioned approximately side-by-side. The baffles 114 are desirably ofa highly thermally conductive material such as aluminum, copper or othermaterial known in the art. The baffles 114 may sealably join to thehousing 64 about the perimeter of each baffle 114. Similarly, thebaffles 114 may sealably join to the conduit 50, preventing vapor flowtherebetween. The conduit 50 extends through the baffles 114 andchambers 104, 106, 108, 110 and 112. FIG. 9 shows the baffles 114defining apertures 116 in opposing portions 118 of adjacent baffles 114with the conduit 50 removed for clarity. “Opposing portions” 118 is arelational term between adjacent baffles 114 that is defined such thatvapor flowing through the apertures 116 of a first baffle 114 willgenerally flow through a matrix of conduit 50 to pass through theaperture 116 in the next baffle 114. The matrix of conduit 50 mayinclude eighteen, more or less, ¾″ by 12″ aluminum tubes. Opposingportions 118 may be diagonal as shown in FIG. 9, right and left sides(See FIG. 10), top and bottom or oriented in generally oppositedirections of the center. FIG. 10 is similar to FIG. 9, but with theconduit 50 in place such that the tortuous path of vapors is readilyapparent.

Fuel 22 in the first chamber 104 is in flowable communication with thechambers 100, 102, 104 and 106 through apertures 116. Fifth chamber 112,assuming five chambers are present, is joined to an outlet 120, which inturn is joined to engine 24. Fuel 22 in the fifth chamber 112 is inflowable communication with the engine 24.

Mist Evaporator and Boiler

From the above description, one skilled in the art will notice that thefuel mist 22 flows through a highly tortuous path. Conversely, fuel 22that is not well vaporized, e.g. large droplets, will not fully travelthe length of the tortuous path and will pool in one of the chambers104, 106, 108, 110, or 112. The baffles 114 with apertures 116 incombination with the housing 64, which define chambers 104, 106, 108,110, and 112, and conduit 50, therefore, constitute a mist evaporator 18converting the fuel 22 in mist form to vapor fuel 22. The baffles 114and housing 64 define a portion of the fuel passageway 96 through whichfuel 22 in mist form may pass, while the conduit 50 vaporizes the mist.

The fuel droplets 22 that are too large for traveling the tortuous pathtemporarily form a pool in one of the chambers 104, 106, 108, 110, and112. The conduit 50, baffles 114 and housing 64 are all of highlythermally conductive material and cooperatively form a boiler 20. Theconduit 50 is in thermal communication with the baffles 114. The baffles114 are in thermal communication with the housing 64. The baffles 114and housing 64 contain and are in thermal communication with a pool offuel 22. Heat energy from the conduit 50 is thermally conducted to thebaffles 114 and housing 64, which in turn transfer the heat energy tothe fuel 22 causing evaporation. The housing 64, baffles 114, andconduit 50 may simultaneously be a mist vaporizer 18 and boiler 20. Thatis, the mist vaporizer 18 and boiler 20 are integrated.

The conduit 50 aids in converting fuel 22 in mist form into vaporcapable of traveling the tortuous path and also adds to the tortuousnature of the fuel passageway 96 inside the vaporizer 16. The conduit50, which may be in thermal communication with the exhaust 30 and may bein thermal communication with the fuel 22 in a mist form, transfers heatenergy from the exhaust 30 contained in the conduit 50 to the fuel 22.Fuel 22 in a mist form may be refined into vapor suitable for travelingthe fuel passageway 96. The conduit 50 transfers heat energy from theexhaust 30 to the baffles 114 and housing 64, which in turn transfer theheat energy to the fuel 22, pooled in any of the chamber 104, 106, 108,110, and 112, causing evaporation and making the fuel 22 sufficientlyvaporized to travel the fuel passageway 96. The conduit 50 is preferablyarranged in a matrix suitable for enhancing the tortuous nature of thefuel passageway 96.

The number of chambers is one factor that has been found important tothe completeness of the vaporization process. When too few chambers areused, pooling of fuel 22 can occur faster than the boiling and the mistdoes not fully vaporize. Increasing the number of chambers increases thevaporization of the fuel 22 whether in pool or mist form. The preferrednumber of chambers is five, as shown, given the dimensions of the othercomponents. One skilled in the art can see that altering the othercomponents will impact the preferred number of chambers. Each of thechambers 104, 106, 108, 110, and 112 preferably define an internal areathat is larger than the area contained within the conduit 50, since thefuel 22, not the exhaust 30, expands in volume inside the vaporizer 16.

In Operation

The engine 24 combusts fuel 22, creating exhaust 30. The exhaust 30flows out through the exhaust outlet 32 into the exhaust line 34.Exhaust 30 divides into two portions at the exhaust valve 36, sendingone portion through the recycling passageway 48 and the balance remainsin the exhaust passageway 40. Exhaust 30 in the recycling passageway 48is moved into the vaporizer 16 and more particularly inside the conduit50 inside the vaporizer 16. Heat energy from the exhaust 30 istransferred to the fuel 22 directly and indirectly through the conduit50 to vaporize the fuel 22. Thereafter, the exhaust 30 is directed backinto the exhaust passageway 40. Exhaust 30 in the exhaust passageway 40downstream of the exhaust valve 36 may pass through various conditioningapparatus such as a catalytic converter 42 and muffler 44 prior to beingreleased into the atmosphere.

Simultaneously, fuel pump 76 draws and pushes the fuel 22 from the fueltank 70 into the fuel line 72 and ultimately into the vaporizer 16 andengine 24. The fuel 22 may be conditioned in the fuel filter 74,t-splitter 78, either throttle 88 or alternatively injector 98, atomizer100, and vaporizer 16. Fuel 22, passing through the throttle 88 and intothe engine 24 does so in a standard manner. The flow of the fuel 22 maybe switched away from the throttle 88 and to the vaporizer 16.

When fuel 22 is directed to the vaporizer, the flow meter 94 controlsthe flow rate of the fuel 22 to the vaporizer 16. The injector 98propels fuel 22 at the atomizer 100, splitting the fuel 22 into a mistform. The mist enters the first chamber 104, receiving heat energyindirectly from the exhaust 30. Inside the vaporizer 16, the liquid fuel22 from the mist may pool. Fuel 22 in a mist form travels through thematrix of conduit 50 and apertures 116 while being converted to vapor.Fuel 22 in pools is maintained inside one or more of the chambers 104,106, 108, 110, and 112. The liquid fuel 22 is boiled until it achievesvaporization and can then travel the fuel passageway 96 into the engine24. The engine 24, thereafter, combusts the vaporized fuel 22.

The present invention has been described with reference to the drawingsin a manner to fully disclose the best mode of making and using thepresent invention. The description is explanatory in nature and is notintended to identify and describe all possible modifications that fallwithin the scope of the claims. Substantive and material changes may bemade without departing from the spirit and scope of the presentinvention.

Direct Fuel Injection

FIG. 11 is a schematic of a fuel vaporizer with fuel injectors. and aheat exchanger. FIG. 11 shows a fuel system 1100 including a vaporizer1116 having a plurality of chambers 104, 106, 108, 110, 112 and aplurality of fuel injectors 1180 instead of a carburetor system. Eachfuel injectors 1180 having nozzles 1170 extending into the housing 64 ofthe vaporizer 1116 to direct inject fuel 22 into the chambers 104, 106,108, 110, 112. The nozzles 170 create a spray 1160 of fuel 22 in, forexample, the first chamber 104. The spray 1160 of fuel 22 may be anatomized mist of fuel 22. The fuel pump 76 draws and pushes the fuel 22from the fuel tank 70 into the fuel line 72 and ultimately into thenozzles 1170 of the fuel injectors 1180.

In operation, an airflow supplied to the first chamber 104 of thevaporizer 1116 encounters the spray 1160 of fuel 22 from the nozzle 1170of the fuel injector 1180. The airflow travels the fuel passageway 96through the first chamber 104, and the conduits 50 heat the airflow andfuel 22 to vaporize a portion of the fuel 22 into the airflow. Theairflow and fuel 22 travel the fuel passageway 96 into the remainingchambers 106, 108, 110, 1112 and conduit to be heated by the conduits50, resulting in increased vaporization of the fuel 22 into the airflow.

In addition to the number of chamber, the number and location of thefuel injectors 1180 is another factor that has been found important tothe completeness of the vaporization process. Increasing the number ofinjectors in each chamber, or the number of chambers having injectorsaffects the vaporization of the fuel 22. In some aspects, the firstchamber 104 includes two fuel injectors 1180 and the second 106 andthird chambers 108 include one fuel injector each. One skilled in theart can see that altering the other components will influence thepreferred number of injectors. In some aspects, the vaporizer isdesigned to create 80% saturation of the fuel 22 in the airflow throughfuel passageway 96 at the exit from the fuel vaporizer 1116.

Another factor that is important in the operation of the fuel injectionvaporizer 1116 is the temperature of the airflow though the plurality ofchambers 104, 106, 108, 110, 112. One skilled in the art can see thataltering the components will influence the temperature of the airflowthrough each chambers. In some examples, the airflow though the fuelpassageway 96 exits the first chamber 104 at 750° F. In some examples,the airflow though the fuel passageway 96 exits the fifth chamber 112,or the final chamber, at 450° F. In some examples, the airflow thoughthe fuel passageway 96 is delivered to the internal combustion engine 24at 375° F. One skilled in the art can see that altering the propertiesor types of fuel 22 will influence the temperatures necessary to achievea desired vaporization of the fuel 22 though the fuel passageway 96.

Heat Exchanger

FIGS. 12A and 12B are schematics of a fuel vaporizer with fuelinjectors. FIG. 12A shows a heat exchanger 1201 including a plurality ofbaffles 1212 forming an air pathway 95 from an air intake 1202 to anaperture 1203 into the first chamber 104 of the housing 64 of the fuelvaporizer 1116. In operation, the heat exchanger 1201 is positionedadjacent to the housing 64 of the fuel vaporizer 1116 and transfersthermal energy from the housing 64 of the fuel vaporizer 1116 to anairflow in the air pathway 31. In some examples, the heat exchanger 1201improves the operation of the fuel vaporizer 1116 by increasing thetemperature of the airflow entreating the first chamber 104, whichresults in faster heating of the airflow in the first chamber 104 andincreased vaporization of fuel 22 in the airflow in the first chamber104.

FIG. 12B shows a vaporizer system 1210 including a heat exchanger 1201and a fuel vaporizer 1116. FIG. 12B is a cross section of a fuelvaporizer 1116 through the first chamber 104. The conduits 50 passingthrough the baffle 114 of the first chamber 104 are visible, as areturbulators positioned in the conduits 50. The heat exchanger 1201includes an air intake 1202 accepting a flow of air and an aperture 1203into the first chamber 104 of the housing 64 of the fuel vaporizer 1116.The heat exchanger 1201 is thermally coupled with the housing 64 of thefuel vaporizer 1116. FIG. 12B shows a nozzle 1170 of a fuel injector1160 positioned adjacent to the air pathway 95 from the heat exchanger1201 entering the first chamber 104. An atomized spray 1180 of fuel isshown in the air pathway 95, where the fuel passageway 96 begins. Thefuel passageway 96 passes through the conduits 50 and into an aperture115 leading to the second chamber 106.

FIG. 12B also shows electric heating elements 1290, 1291 thermallycoupled with the fuel vaporizer 1116. A first set of electric heatingelements 1290 runs along the conduits 50, and a second set of electricheating elements 1291 are coupled to the baffle 114 between the firstchamber 104 and the second chamber 106. The electric heating elements1290, 1291 are in the fuel passageway 96 and enable electric power toheat the conduits 50 and the baffle 114 and, therefore, transfer thermalenergy to the airflow in the fuel passageway 96.

In operation, the electric heating elements 1290, 1291, in someinstances, supplement to the heat transfer from the exhaust gas 30 inthe conduits, in order to maintain desired airflow temperatures orvaporization levels along fuel passageway 96. For example, if theinternal combustion engine 24 is at an idle condition, the thermaloutput from the exhaust gas 30 may not be sufficient to maintain adesired vaporization level of fuel 22 in the fuel passageway 96, and theelectric heating elements 1290, 1291 are used to maintain the desiredvaporization level of fuel 22 entreating the internal combustion engine24 to maintain operation. In some instances, the electric heatingelements 1290, 1291 are powered by a battery onboard a vehicle havingthe internal combustion engine 24. The vehicle may be an electric hybridvehicle having a primary electric motor providing propulsion, and aninternal combustion engine 24 operating a generator to supply theelectric motor with power directly, or to a battery system supplying theelectric motor. In some instances, the internal combustion engine 24 ismechanically coupled to a generator for steady-rpm changing of thebattery. The electric heating elements 1290, 1291 may be used, forexample, to maintain regulate the airflow temperatures or vaporizationlevels along fuel passageway 96 if, for example, the power demand of theinternal combustion engine 24 drops.

In some instances, the electric heating elements 1290, 1291 enable acold-start of the internal combustion engine 24 by pre-heating theconduits 50 and baffles 114 before the internal combustion engine 24 isstarted, and the while internal combustion engine 24 is warming up. Insome instances, the internal combustion engine 24 includes a traditionalfuel injection system that operators the internal combustion engine 24during a cold-start, and the fuel injector system 1210 is heated by theexhaust gas 30 until the vaporized 1116 is able to supply vaporized fuel22 to the internal combustion engine 24. Once vaporized fuel 22 isdelivered to the internal combustion engine 24, the traditional fuelinjection system may be disabled.

There has been described novel apparatus and techniques in connectionwith fuel vaporization using fuel injectors. It is evident that thoseskilled in the art may make numerous modifications of and departuresfrom the specific apparatus and techniques herein disclosed withoutdeparting from the inventive concepts. Consequently, the invention is tobe construed as embracing each and every novel concept and combinationof concepts disclosed herein and limited only by the spirit and scope ofthe appended claims.

What is claimed is:
 1. A fuel vaporizer, comprising: a housingcomprising: a plurality of baffles joined to the housing, the housingand baffles defining a plurality of chambers, each of the plurality ofbaffles defining an aperture between adjacent chambers, an air inlet ina first chamber of the plurality of chambers, an vapor outlet in a lastchamber of the plurality of chambers, the apertures defining a flow pathfrom the air inlet, through the plurality of chambers, and to the vaporoutlet, and a conduit extending through the baffles and chambers, theconduit adapted to accept a flow of exhaust gas there through, theconduit positioned in the flow path, and the conduit adapted to transferthermal energy from the exhaust gas to an airflow along the flow path;and a fuel injector positioned in an opening in the housing, the fuelinjector adapted to inject fuel into the flow path in the first chamber,wherein the housing is adapted to accept the airflow at the air inletand produce a flow of vaporized fuel to the vapor outlet, the thermalenergy from the conduit vaporizing the fuel injected into the airflowand producing the flow of vaporized fuel.
 2. The fuel vaporizer of claim1 wherein the fuel vaporizer defines an exhaust inlet chamber and anexhaust outlet chamber in flowable fluid communication through theconduit.
 3. The device of claim 1, wherein the conduit is a matrix of aplurality conduits.
 4. The device of claim 1, wherein the conduitincludes a turbulator joined inside the conduit.
 5. The fuel vaporizerof claim 1, further including an electric heating element adapted toheat the conduit, the heating element enabling electric heating of theairflow through the flow path.
 6. The fuel vaporizer of claim 5, whereinthe heating element is integrated with the plurality of baffles.
 7. Thefuel vaporizer of claim 5, wherein the heating element is integratedwith the conduit.
 8. The fuel vaporizer of claim 1, further including: aheat exchanger in thermal connection with the outer surface of thehousing, the heat exchanger defining an internal flow path in flowablefluid communication with the air inlet of the housing, the heatexchanger being adapted to heat the airflow along the internal flow pathwith thermal energy from the housing prior to the airflow entering theair inlet of the housing.
 9. The fuel vaporizer of claim 1, wherein thefuel injector is a first fuel injector in a first opening in thehousing, the fuel vaporizer further comprising a second fuel injectorpositioned in a second opening in the housing, the second fuel injectoradapted to inject fuel into the flow path in the first chamber.
 10. Thefuel vaporizer of claim 1, wherein the fuel injector is a first fuelinjector in a first opening in the housing, the fuel vaporizer furthercomprising a second fuel injector positioned in a second opening in thehousing, the second fuel injector adapted to inject fuel into the flowpath in a second chamber, the second chamber being adjacent to the firstchamber.
 11. The fuel vaporizer of claim 10, further comprising a thirdfuel injector positioned in a third opening in the housing, the thirdfuel injector adapted to inject fuel into the flow path in a thirdchamber, the third chamber being adjacent to the second chamber.
 12. Amethod of operating an internal combustion engine, given a fuel, anairflow, and exhaust gas from the internal combustion engine, the methodcomprising: flowing the exhaust gas through a conduit, the conduitpassing through a plurality of chambers formed by a plurality ofbaffles, the exhaust gas transferring thermal energy to the conduit;flowing the airflow through the plurality of chambers, the airflowflowing around the conduit; injecting the fuel in the airflow of a firstchamber of the plurality of chambers, the injecting atomizing the fuelin the airflow; transferring thermal energy from the conduit to theairflow in the plurality of chambers, the thermal energy vaporizing atleast a portion of the fuel in the airflow and generating a flow ofvaporized fuel; and providing the flow of vaporized fuel to an intake ofthe internal combustion engine.
 13. The method of claim 12, whereinflowing the exhaust gas through a conduit comprises flowing the exhaustgas through a matrix of a plurality of conduits.
 14. The method of claim13, wherein flowing the airflow through the plurality of chamberscomprises flowing the airflow through the matrix of the plurality ofconduits in each of the plurality of chambers.
 15. The method of claim12, wherein flowing the exhaust gas through a conduit further comprisesadding turbulence to the flow of exhaust gas inside the conduit.
 16. Themethod of claim 12, further including injecting the fuel in the airflowin a second chamber of the plurality of chambers.
 17. The method ofclaim 12, wherein transferring thermal energy from the conduit to theairflow in the plurality of chambers comprises heating the airflow inthe first chamber to at least 725 degrees Fahrenheit.
 18. The method ofclaim 17, wherein transferring thermal energy from the conduit to theairflow in the plurality of chambers comprises heating the airflow in alast chamber to at least 450 degrees Fahrenheit.
 19. The method of claim12, wherein the thermal energy vaporizing at least a portion of the fuelin the airflow, comprises vaporizing at least 50% of the fuel.
 20. Themethod of claim 12, wherein the thermal energy vaporizing at least aportion of the fuel in the airflow, comprises vaporizing at least 80% ofthe fuel.
 21. The method of claim 12, further comprising transferringthermal energy to the conduit with an electric heating element.
 22. Themethod of claim 21, wherein transferring thermal energy to the conduitwith an electric heating element comprises regulating a temperature ofthe airflow using the transferring of thermal energy to the conduit fromthe electric heating element.
 23. The method of claim 22, wherein theregulating based on a temperature of one or more of the following: theexhaust gas, the conduit, and the airflow.
 24. The method of claim 12,wherein flowing the exhaust gas through a conduit comprises regulatingthe flow of exhaust gas through the conduit to maintain a temperature ofthe airflow in at least one of the first chamber and the intake.
 25. Themethod of claim 12, further including: prior to the injecting the fuelin the airflow of a first chamber, starting the internal combustionengine using a fuel injection system of the internal combustion engine,and transitioning from the fuel injection system of the internalcombustion engine to injecting the fuel in the airflow of a firstchamber, the transitioning being based on a temperature of the airflowor a temperature of the conduit.
 26. A method of operating an internalcombustion engine, given a fuel, an airflow, and exhaust gas from theinternal combustion engine, the method comprising: flowing the exhaustgas through a conduit, the conduit passing through a plurality ofchambers formed by a plurality of baffles, flowing the airflow throughthe plurality of chambers, the airflow flowing around the conduit;injecting the fuel in the airflow of a first chamber of the plurality ofchambers, the injecting atomizing the fuel in the airflow; transferringthermal energy from an electric heating element to the airflow in theplurality of chambers, the thermal energy vaporizing at least a portionof the fuel in the airflow and generating a flow of vaporized fuel; andproviding the flow of vaporized fuel to an intake of the internalcombustion engine.